Method wait_for

src/bthread/condition_variable.h:82–85

Unlike std::condition_variable, we return ETIMEDOUT when time expires rather than std::timeout

    // Unlike std::condition_variable, we return ETIMEDOUT when time expires
    // rather than std::timeout
    int wait_for(std::unique_lock<bthread::Mutex>& lock,
                 long timeout_us) {
        return wait_until(lock, butil::microseconds_from_now(timeout_us));
    }

    int wait_for(std::unique_lock<bthread_mutex_t>& lock,
                 long timeout_us) {